slog: Webhook handler

A webhook Handler for slog Go library.

^{Sponsored by:}

Cloud-native search engine for observability - An OSS alternative to Splunk, Elasticsearch, Loki, and Tempo.

See also:

slog-multi: slog.Handler chaining, fanout, routing, failover, load balancing...
slog-formatter: slog attribute formatting
slog-sampling: slog sampling policy
slog-mock: slog.Handler for test purposes

HTTP middlewares:

slog-gin: Gin middleware for slog logger
slog-echo: Echo middleware for slog logger
slog-fiber: Fiber middleware for slog logger
slog-chi: Chi middleware for slog logger
slog-http: net/http middleware for slog logger

Loggers:

slog-zap: A slog handler for Zap
slog-zerolog: A slog handler for Zerolog
slog-logrus: A slog handler for Logrus

Log sinks:

slog-datadog: A slog handler for Datadog
slog-betterstack: A slog handler for Betterstack
slog-rollbar: A slog handler for Rollbar
slog-loki: A slog handler for Loki
slog-sentry: A slog handler for Sentry
slog-syslog: A slog handler for Syslog
slog-logstash: A slog handler for Logstash
slog-fluentd: A slog handler for Fluentd
slog-graylog: A slog handler for Graylog
slog-quickwit: A slog handler for Quickwit
slog-slack: A slog handler for Slack
slog-telegram: A slog handler for Telegram
slog-mattermost: A slog handler for Mattermost
slog-microsoft-teams: A slog handler for Microsoft Teams
slog-webhook: A slog handler for Webhook
slog-kafka: A slog handler for Kafka
slog-nats: A slog handler for NATS
slog-parquet: A slog handler for Parquet + Object Storage
slog-channel: A slog handler for Go channels

🚀 Install

go get github.com/samber/slog-webhook/v2

Compatibility: go >= 1.21

No breaking changes will be made to exported APIs before v3.0.0.

💡 Usage

GoDoc: https://pkg.go.dev/github.com/samber/slog-webhook/v2

Handler options

type Option struct {
  // log level (default: debug)
  Level     slog.Leveler

  // URL
  Endpoint string
  Timeout  time.Duration // default: 10s

  // optional: customize webhook event builder
  Converter Converter
  // optional: custom marshaler
  Marshaler func(v any) ([]byte, error)
  // optional: fetch attributes from context
  AttrFromContext []func(ctx context.Context) []slog.Attr

  // optional: see slog.HandlerOptions
  AddSource   bool
  ReplaceAttr func(groups []string, a slog.Attr) slog.Attr
}

Other global parameters:

slogwebhook.SourceKey = "source"
slogwebhook.ContextKey = "extra"
slogwebhook.ErrorKeys = []string{"error", "err"}
slogwebhook.RequestIgnoreHeaders = false

Supported attributes

The following attributes are interpreted by slogwebhook.DefaultConverter:

Atribute name	`slog.Kind`	Underlying type
"user"	group (see below)
"error"	any	`error`
"request"	any	`*http.Request`
other attributes	*

Other attributes will be injected in extra field.

Users must be of type slog.Group. Eg:

slog.Group("user",
  slog.String("id", "user-123"),
  slog.String("username", "samber"),
  slog.Time("created_at", time.Now()),
)

Example

import (
	"fmt"
	"net/http"
	"time"

	slogwebhook "github.com/samber/slog-webhook/v2"

	"log/slog"
)

func main() {
  url := "https://webhook.site/xxxxxx"

  logger := slog.New(slogwebhook.Option{Level: slog.LevelDebug, Endpoint: url}.NewWebhookHandler())
  logger = logger.With("release", "v1.0.0")

  req, _ := http.NewRequest(http.MethodGet, "https://api.screeb.app", nil)
  req.Header.Set("Content-Type", "application/json")
  req.Header.Set("X-TOKEN", "1234567890")

  logger.
    With(
      slog.Group("user",
        slog.String("id", "user-123"),
        slog.Time("created_at", time.Now()),
      ),
    ).
    With("request", req).
    With("error", fmt.Errorf("an error")).
    Error("a message")
}

Output:

{
  "error": {
    "error": "an error",
    "kind": "*errors.errorString",
    "stack": null
  },
  "extra": {
	"release": "v1.0.0"
  },
  "level": "ERROR",
  "logger": "samber/slog-webhook",
  "message": "a message",
  "request": {
    "headers": {
      "Content-Type": "application/json",
      "X-Token": "1234567890"
    },
    "host": "api.screeb.app",
    "method": "GET",
    "url": {
      "fragment": "",
      "host": "api.screeb.app",
      "path": "",
      "query": {},
      "raw_query": "",
      "scheme": "https",
      "url": "https://api.screeb.app"
    }
  },
  "timestamp": "2023-04-10T14:00:0.000000",
  "user": {
	"id": "user-123",
    "created_at": "2023-04-10T14:00:0.000000"
  }
}

Tracing

Import the samber/slog-otel library.

import (
	slogwebhook "github.com/samber/slog-webhook"
	slogotel "github.com/samber/slog-otel"
	"go.opentelemetry.io/otel/sdk/trace"
)

func main() {
	tp := trace.NewTracerProvider(
		trace.WithSampler(trace.AlwaysSample()),
	)
	tracer := tp.Tracer("hello/world")

	ctx, span := tracer.Start(context.Background(), "foo")
	defer span.End()

	span.AddEvent("bar")

	logger := slog.New(
		slogwebhook.Option{
			// ...
			AttrFromContext: []func(ctx context.Context) []slog.Attr{
				slogotel.ExtractOtelAttrFromContext([]string{"tracing"}, "trace_id", "span_id"),
			},
		}.NewWebhookHandler(),
	)

	logger.ErrorContext(ctx, "a message")
}

🤝 Contributing

Ping me on twitter @samuelberthe (DMs, mentions, whatever :))
Fork the project
Fix open issues or request new features

Don't hesitate ;)

# Install some dev dependencies
make tools

# Run tests
make test
# or
make watch-test

samber/slog-webhook